Children who have operations to correct heart defects do better if the surgeon has help from a robot, says a study.

The direct comparison of human and robot assisted ops was carried by the University of Michigan.

Researchers found that after an operation involving a robot a child spent less time in hospital and suffered reduced complications.

But robots can only be used on children weighing 10kg or more, and many defects are fixed shortly after birth.

Robot-assisted surgery is becoming more common in the US and UK, and may in future be used to carry out a range of operations, including heart bypasses.

Its biggest advantage is that it allows the surgeon to carry out some procedures normally linked to "open chest" techniques with "keyhole" surgery instead, which is far less traumatic.

It involves three probes inserted through small incisions - one carries a tiny camera, and the others can wield various surgical instruments.

The Da Vinci machine in use in the US and UK costs $1 million.

Shorter stays

The University of Michigan study looked at seven children who underwent heart surgery using the robot.

In five or so years, perhaps we'll perform most of the basic procedures with the robot's help

Dr Richard Ohye, University of Michigan

The robot operations took longer, but some children involved were home within a couple of days - a shorter time in general than children undergoing the same procedure with "open chest" techniques.

None of the children were treated for structural defects of the heart itself, such as "hole-in-the-heart". Instead their defects included abnormally-formed blood vessels, and the insertion of a pacemaker to correct a heart rhythm abnormality.

Whether the technique would ever be appropriate for more complex heart defect correction is not yet proven.

The sheer size of the robot probes mean that they cannot be fitted between the ribs of a baby under 10 kg in weight - the approximate weight of a one-year-old.

Future expansion

Surgeon Richard Ohye said: "Robot-assisted surgery has already shown quite a bit of promise in the adult population, including adults who have congenital heart anomalies.

"But we feel from our experience that it can be used on many paediatric patients weighing more than 10kg, and can reduce hospital stays, operative trauma, cosmetic impact and overall recovery time.

"We found it does so with an acceptable impact on a patient's time in the operating room.

"In five or so years, perhaps we'll perform most of the basic procedures with the robot's help."